The -18°C standard for frozen food storage was set over 100 years ago and hasn’t changed since.
Technology has evolved. Food science has advanced. Customer expectations have shifted. And yet, that temperature of -18°C has remained steadfastly the same.
What’s more surprising is that the standard is rooted in 0°F (-17.8°C), not in any precise scientific measure of how water freezes within food. In fact, a report by Science Direct states that this number was arbitrarily chosen. At -18°C, most foods never reach 100% frozen water content, typically sitting closer to 95%.
And that long-standing benchmark is increasingly being challenged.
Following the release of the Three Degrees of Change report there’s a growing, evidence-backed push to raise the standard to -15°C. The argument is that a small shift could deliver a meaningful environmental benefit without compromising food integrity.
What’s in a number?
Nomad Foods, the company behind the likes of Birds Eye, Findus and Iglo, commissioned a landmark twelve-month pilot study with food research centre Campden BRI. Nine frozen savoury products were tested across four temperatures ranging from -18°C to -9°C, assessed against eight criteria including food safety, texture, nutrition, energy use and packaging impact.
Results of the study showed that whilst there were some sensory changes in mixed vegetables at -9°C and salmon fillets at -12°C, and some impact on Vitamin C in vegetable products at the highest temperature tested, overall, there was no significant change to products across the areas tested; in fact, freezer energy consumption fell by 10 to 11%.
The energy and carbon numbers
Applied at scale, those figures become substantial. According to MultiModal, a move to -15°C across the industry could save 17.7 million metric tonnes of CO2 per year, that’s the equivalent annual emissions of 3.8 million cars. It could also cut costs in the supply chain by at least 5% and in some areas by up to 12%.
The reason the numbers stack up is straightforward: every degree below zero requires 2 to 3% more energy to maintain. Three degrees, multiplied across every freezer, every vehicle and every warehouse in the supply chain, adds up quickly.
The impact on transportation
This is where it gets more complex for operators like Keep It Cool.
Current regulation sets the transport temperature for frozen goods at -18°C or below. A temporary tolerance of up to -15°C is permitted during loading and unloading, provided average temperature compliance is maintained throughout. Any prolonged rise above -15°C constitutes a cold chain breach.
In practice, however, many transport operators are routinely asked to set vehicle temperatures between -21°C and -25°C for UK-wide distribution.
This is not only significantly colder than the regulation requires, but it’s also significantly further away from the -15°C target the industry is actively working towards. Therefore, until the regulatory framework shifts and customer specifications follow, transport operators have limited wriggle room.
There is also a shelf-life consideration worth noting: if manufacturers respond to a warmer storage standard by reducing declared shelf life on packaging, there is a risk of increased consumer food waste that would offset some of the environmental gains.
Therefore, the savings for transport are possible but minimal. The biggest gains sit in cold storage and warehousing. For the change to reach its full potential, the whole chain needs to move as a collective, and that requires coordinated action across manufacturers, retailers, logistics operators and regulators.
The direction of travel
The momentum is building. The Move to -15°C has more than doubled its membership since launching in 2023, with stakeholders from every stage of the supply chain now represented. The British Frozen Food Federation has been vocal in its support, with chief executive Rupert Ashby describing the Nomad Foods findings as a significant step forward, one with real implications for carbon emissions, energy costs and commercial margins.
For Keep It Cool, this is not a distant policy debate. It is a conversation happening at the heart of the industry we serve every day. We will continue to follow the evidence, engage with the sector and adapt our operations as the regulatory and commercial landscape evolves. When the framework moves, we will be ready to move with it.
